PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 OR WHO 0-2 Life expectancy: Not specified Hematopoietic: Hemoglobin greater than 10 g/dL Neutrophil count greater than 2,000/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) Alkaline phosphatase no greater than 2.5 times ULN (5 times ULN if liver metastases present) Transaminases no greater than 2.5 times ULN (5 times ULN if liver metastases present) Renal: Creatinine no greater than 1.7 mg/dL Cardiovascular: Clinically normal cardiac function No history of severe or unstable ischemic heart disease 12-lead ECG normal Other: No history of unstable systemic disease No concurrent uncontrolled diabetes mellitus No concurrent infection No history of hypersensitivity to sulfonamides No other malignancy within the past 5 years except cone-biopsied carcinoma of the cervix or adequately treated basal cell or squamous cell skin cancer No psychological, familial, sociological, or geographical condition that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception